will travel to newtown this afternoon to console the victim's families and to attend a community vigil. this headlines sums up where we are nearly 48 hours after the shooting, wrenching detailing but few answers. we want to start with nbc correspondent pete williams about what we are learning about the investigation. do we know more about why it happened? >> i don't think we can ever get a satisfactory answer, there is no satisfactory answer to such a heinous act. there's some evidence at his mother's house, they have a commuter there and they're analyzing that to see what they can get out of it. >> what was the scenario? >> the scenario, it all starts friday morning when he takes his mother's gun, she had purchased them legally, this is a woman who grew up in rural new hampshire, was comfortable can guns, liked them. he kills her, takes three of those guns to the school, in her car, forces his way in by shattering the window. they had a buzzer system and he forced his way in. the principal tried to stop him and he concentrated his firepower on these two classrooms with devastating eff
